The subject matter herein relates generally to sealed bulkhead connector assemblies.
Automatic transmissions in some automobiles may include a transmission case that has wires extending from the case or a connector joined to the case. The wires may be coupled with other components or the connector may be joined with another connector in the automobile to transfer power and signal to and from the transmission. These inputs may be used to shift or change gears in the transmission, or operate a pump of the transmission, for example.
The wires or connectors exit from the transmission case from openings in the case. These openings may need to be sealed in order to prevent contaminants from outside of the transmission case, such as moisture, dirt, and the like, from entering into the transmission case via the openings. Additionally, the openings may need to be sealed to prevent contaminants inside the transmission case, such as transmission fluid, from exiting the transmission case via the openings.
Additionally, the cavity for the terminal within the connector must be sealed from contaminants. In current applications, a seal is provided at the terminal entry side, either with a mat type seal or individual wire seals that are crimped to the terminal. These types of seals are typically made from silicone which is not compatible with all automatic transmission fluids (ATF). Additionally, both of these seal types squeeze the outside of the wire insulation to provide sealing. This would require the use of fluid blocked (anti-capillary) wire to prevent fluid from wicking under the insulation and past the seal.
Along with proper sealing, the terminals must be completely inserted into the connectors to provide a complete electrical connection. In some current designs, the connector may be assembled with the terminals not positioned correctly or completely seated within the connector. A terminal position assurance feature is required to assure the correct position of the terminal. In addition to checking for partially installed terminals, a Terminal Position Assurance (TPA) feature such as an Independent Secondary Lock (ISL) will also provide enhanced terminal retention force when properly seated.
Oil or fluid blocking connector designs today are not well featured to assure proper connector assembly and sealing. Some “state of the art” systems offer a Terminal Position Assurance (TPA) device, but these are only Primary Latch Reinforcing (PLR) designs and do not offer an Independent Secondary Lock (ISL) which provides terminal retention even if the primary latch were to fail. In addition, previous designs having a front loaded TPA are often potted with sealant behind the TPA which is risk prone due to the need to having the sealant flow around various irregularly shaped components while not having it escape through to the point of creating a leak path through to the other side. With that approach, it is difficult to assure proper sealant dispensing in all areas since the sealant cannot be seen visually in all areas behind the TPA.
Other sealing approaches are used in industry as well such as using fluid blocking wire which contains silicone as a blocking material within the wire strands. It is expensive, stiff to the point of causing risk for terminal crimp failures, and for automatic transmission applications the use of silicone in the fluid area is a problem due to material breakdown.
A need exists for a bulkhead connector that solves these problems.